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2005
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July
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In the Laboratory
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An Experimental Introduction to Interlaboratory Exercises in Analytical Chemistry
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L. Puignou and M. Llauradó
Departament de Química Analitica, Facultat de Química, Universitat de Barcelona, E-08028 Barcelona, Spain
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July 2005
Vol. 82 No. 7
p. 1079
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| Abstract |
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An experimental exercise on analytical proficiency studies in collaborative trials is proposed. This practical provides students in advanced undergraduate courses in chemistry, pharmacy, and biochemistry, with the opportunity to improve their quality assurance skills. It involves an environmental analysis, determining the concentration of a contaminant (hexavalent chromium) in a synthetic reference sample simulating wastewater. A variety of analytical measurement techniques were compared: molecular absorption spectroscopy, flame atomic absorption spectroscopy, and differential pulse polarography. Furthermore, several complementary techniques for sample preparation such as liquid–liquid extraction and coprecipitation were also involved. The students acted as individual laboratories in a round-robin test, and the analytical results were evaluated in terms of precision and accuracy using a range of statistical tools such as visual display methods. Several causes of systematic error and strategies to improve the reliability of measurements were discussed.
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| Supplement |
Instructions for the students, including detailed procedures, materials and reagents, and hazard alerts, and notes for the instructor, including a summary of the statistics and several comments on the experiment, are available.
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 Contents |
JCE2005p1079W.doc (Microsoft Word)
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| More Information |
Citation |
Puignou, L.; Llauradó, M. J. Chem. Educ. 2005 82 1079.
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Keywords |
Analytical Chemistry; Chemometrics; Hands-On Learning / Manipulatives; Instrumental Methods; Laboratory Instruction; Quantitative Analysis; Testing / Assessment; Upper-Division Undergraduate
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History |
Created:
Last Updated: |
May 31, 2005
June 8, 2005
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| Home > JCE Print > Journal of Chemical Education > Issues >
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1079
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